Thermoplastic compositions



- terials like-oil resistant product -a rubber with an aryl thermopwhich U I E STATES PATENT OFFICE:

'rnsau'oms'nc comosmons l'aulhLDowney',Nlhc,W.Va.,asslgnortollonlantaChemicalOom poratien Serial No. scam n snucauonmim s, 1m.

'This invention relates to new compositiona. More particularly. thisinvention relates to admixtures oi thermoplastic maimproved properties.

Insccordancewiththisinventionithasbeen found that admixture of abutadiene compound P ymer type synthetic rubber and a rubberobtained bytreating in a issue composition of superior properties and onecharacteristics Imattsinable v with either ingredient separately.Butadiene 1,3 and'related compounds form the p a building structure fora number of synthetic-rubbers and it is with these polymers andco-polymers of butadiene compounds that the present invention isc0ncerned. Some of the 'more important members of this class which areavailable commercially include the neoprenes are polymers of chlorbutadiene, Hycar and Perhunan which are oo-p lymers oi butadiene "andacrylic nitrile and :Buna S, a copolymer of butadiene and styrene.However,

individual plastic com:-

- 1941, and in co-pending application or David J.

Beaver, Serial 110,417,577, illed November 1, 1941.- The methodsot'preparation are fully. described in these disclosures and comprise.in

general, brinsing'a rubber. usually in the preseaos oi anhydrousaluminumchloride, into in- 45 with tolyi dichiorpb n oil and 7 1:01am.(cl. 260-5) thermoplastic timate association with an aryl phosphinehalide as for example, tolyl dichlorphosphine, 1,3,4 trimethyl phenyldichlor Iylyl dichlor phosphine. biphenyl dichlor phosphine.

alpha naphthyl dichlor phosphin'e, tetrahydronaphthyl dichlor phosphine,dichlor phosphine of meta diphenyl benzene, chlor phenyl dichlorphosphine, cymyl dichlor phosphineand retyl phosphine halide results'dichlor phosphine. Particularly in the case of products derived frommononuclear aryl phosphine halides. better resistance to oils andsuperior physical properties result irom'com' .ducting'the treatment ofthe rubber with the phosphine halide in the presence oi. an aromaticpolynuclear hydrocarbon such as phenanthrene. retene or retene oil.Accordingly. it is preferred to employ the po mer or copolymer or abutasize and shape after the diene compound in admixture with arubber-like cu resistant plastic material obtained by treatretene orretene oil. It is imderstood, however, that any vulcanizable elasticthermoplastic product derived from a rubber and aryl phosphine halidewhich, in addition to rubber-like properties, a w: markedly greaterresistance to swelling byoils than natural rub- .ber, can be used andimproved compositions obtained.

The following are examples of suitable, rubher-like oil resistantthermoplastic products: The product obtained by treating pale creperubber with either tolyldichior phosphine or retyl dichlor phosphine,the product'obtained by treating ground truck peels with. retyl dichlorphosphine, the product obtained by treating pale crepe rubber with cymyldichlorfphosphine and retene, the

product obtained by treating pale creperubber with tolyl dibromphosphine and retene, the

product obtained by treating reclaimed rubber with tolyl dichiorphosphine and retene, the product obtained by with xylyl dichlor Dlwphine and retene, the product obtained by treatingground truck peels arubber with an aryl dichlorphosp' hine and naphthyl dichlor phosphine, V

treating ground truck peels the product obtained by treating aco-polymer of butadiene and acrylic nitrile with tolyl dichlor phosphineand retene.

Given below are details of the preparation of typical members of thisgroup. While these illustrate how. rubber-like oil resistant productsare obtained from rubbers and aryl phosphine halides, the presentinvention is not concerned with the preparation of the components ofthenew compositions and is not limited thereto.

A rubber cement was prepared by dissolving 100 parts by weight of palecrepe rubber in a suitable solvent as for example carbon disulflde. Intothe cement so prepared contained in a suitable vessel fitted with areflux condenser and stirring mechanism there was stirred 200 parts byweight of crude naphthyl phosphine dichloride. Heat was then applied andthe mixture stirred at refluxing temperature for about 15 hours afterwhich a Liebig type condenser was substituted for the reflux condenserand the solvent removed by distillation. Heating was continued for ashort time after distillation had substantially ceased and then livesteam was introduced and after a thorough steaming out, the product waswashed with water on a rubber mill or preferably on a mill havingcorrugated rolls or on other equipment adapted for washing tough plasticproducts. The washed product was dried to constant weight as for exampleby milling on a hot mill followed by heating in a vacuum oven. In thismanner there was obtained substantially 180.5 parts by weight of a toughyellow rubbery product. This product was found to cure nicely in thepresence of sulfur'and accelerator and to be resistant to attack bysolvents as for example gasoline and lubricating oil. For example astock was made up as follows, the parts being by weight: 100 parts ofthe above plastic product, .40 Parts Gastex, 10 parts zinc oxide, 5parts whiting, 3 parts .stearic acid, 2 parts, pine tar, 2 parts sulfurand 1.5 parts mercaptobenzothiazole. This stock ave a good cure in 30minutes at the temperature of forty pounds steam pressure per squareinch. The cured product showed almost no swelling in lubricating oilafter four days immersion at room temperature.

A rubber cement was prepared by dissolving substantilly 100 parts byweight of pale crepe rubber in a suitable solvent as for example carbonbisulfide. To the cement so prepared contained in a suitable .vesselfitted with a reflux condenser and stirrer there was added substantially100 parts by weight of a crude tolyl dichlor phosphine. (This was theproduct obtained by reacting toluene with PO13 in the presence ofanhydrous aluminum chloride as described in Liebigs Annalen vol. 212,pp. 206,

207, drawing off the upper layer which separated upon cooling andemploying the lower layer as crude tolyl dichlor phosphine.) Heat wasapplied and after heating and stirring for about an hour, 100 parts byweight of technical retene was added and the heating and stirringcontinued for about twelve hours. A Liebig type condenser was thensubstituted forv the reflux condenser and the solvent removed bydistillation. Heating was continued for a short time after distillationhad substantially ceased and live steam introduced. After a thoroughsteaming out the product was washed with water on a rubber mill orPreferably on a mill having corrugated rolls or on other equipmentadapted for washing tough plastic prodaaemoe ucts. The washed productwas dried to constantweight by milling on a hot mill followed by heatingin a vacuum oven. Substantially 229 parts by weight of a toughbrownrubbery product was obtained. It could be compounded very much likenatural rubber and possessed useful properties not found in the later.For example, a vulcanizate prepared from a stock consisting of 100 partsby weight of the plastic,

10 parts zinc oxide, 0.5 part stearic acid and 1.5

parts mercaptobenzothiazole (all parts are by weight) was highlyresistant to attack by ozone or solvents such as kerosene and benzene.

Substantially 100 parts by weight of ground truck peels were dispersedin a suitable solvent as for example toluene and substantially 80 partsby weight of crude tolyl dichlor phosphine added thereto. The charge.was stirred and heated at about 55 C. for about two hours andsubstantially 80 parts by weight of technical retene added. Heating andstirring at 55 C. was continued for about 18 hours after which thesolvent was removed, preferably by distillation. Heating was continuedfor a short time after distillation had substantially ceased and thenlive steam was introduced. After a thorough steaming out the charge wasremoved and washed with water on a rubber mill, preferably one havingcorrugated rolls, or on other equipment especially adapted for washingtough plastic products. The product was dried by milling on a hot millfollowed by heating to constant weight in a vacuum oven. Substantially202 parts by weight of tough rubbery product resistant'to ozone andsolvents was obtained. Since this product is referred to in specificcompositions set forth to illustrate the invention it will, forconvenience, be hereinafter designated as .scrap rubber derivative. Asset forth in the Beaver application referred to above it has been foundthat any reclaimed or scrap rubber is enormously improved with regard toresistance to solvents and ozone providing that the rubber is treatedwith technical dichlor phosphine equivalent to at least 60 parts byweight of the crude and at least 40 parts by weight of technical reteneor retene oil per 100 parts by weight of the rubber. For best resultsthe proportion of each reactant should be from 70 to parts by weight,the optimum being about 80.

As specific embodiments of the invention illustrating the desirableproperties of the new thermoplastic compositions and in nowise limitingthe invention, stocks were compounded comprising the preferredadmixtures together with compounding and vulcanizing ingredients. Thecomposition of the stocks can best be described by reference tocompounds of the individual plastics.

Cyclohexylamino thiobenzothiazole "sl'lhecompositionoftheflnalatockswssasfol ows:.

The above data show the superior modulus and tensile propertiesexhibited by the preferred admixtures. I

Resistance to abrasion was determined by maintaining portions of thecured stocks in contactwith' an abrasive wheel and measuring the volumeof stock worn away and the power consumed. A description of theapparatus and the 7 method of carrying out the test may be found in A.S. T. M. Standards on Rubber Products, published by the American Societyfor Testing Materials. November 1937, pages 48-50, Method B. a

Cure

Abrasion Stock time in index These results show that the volume ofst cklost on abradins is less in the ease of the preferred mixtures than withNeoprene alone. In addition, all of the stocks were found to be highlyresistant to attack by ozone.

As further specific embodiments vulcani'zable stocks were prepared whichwere essentially mixtures of Compound #2 and a third compoundcomprising:

Mineral acidrearranged fiA-trimethjrl dihydroquinoline DKbenzothiuyIthiol) dimethyl urea..

' Stock I amt A B D E F P u PM. Pam weigh weigh M by PM PM" Compound #1100.0 sso set I W Compound #2-. 12. 0 1a 0 833533 g 3-3 fig The stocksso compounded were cured by heating for different periods of time in apress at g z izf ggg fi E the temperature of 40 pounds of steam pressuretam ratugre of 60 team W per mm maul and tensile MT, inch. The its; an?!tensife we; properties of the cured rubber products are set :g cured rodt pm forth below: e p o Table I Table II 'Modulus of elasticity Modul felastic! cm in lbsJin. at elonga- Temua mt cm 11111337113: at elong-Tenaile ma 5 m tions ofv b tions ofat break took time elonls Stocktimein along" mm. inlbsJin percent mine. v gy m% 400% 1 0% 01:8 140 060not a0 040 i930 2705 s10 28 1,% gfl 2 rag g g 5& gig so 1,245 use am 401.100 2. 116 2855 m0 :3 1, 1'33 20% 5133 40 1,140 2.200 2.660 ass 401,350 also :00

ical properties of the new compositions;

The loss on abrasion was as follows:

It is evident that the volume of stock worn away by the abradina wheelis proanessively diminishedastheHycar-iadilutedbytheseeond plasticcomponent.

Further vuicanizable stocks were prepared which were essentiallymixturesof Compound #2 and a fourth compound comprisins cmnpounasl I Parts byweight Perbunan 100.0 zinc oxide 5.0 Gastex 45.0 Btearic acid 2.5Triphenyl phosphate 2.0 Sulfur 1.0 Mercaptobenzothiaaole 1.5

The complete stocks comprised:

Stock r est we Compound I! 100. 0 90. 0 8!. 0 Compound I2 l0. 0 1- 0Since the preferred combinations of plastic materlals possess increasedplasticity over that or the separate ingredients, it was possible tocompound the H and J stocks in a much shorter time than was required fortheG stock. For example 5 minutes milling was required to produce a goodsheet of Perbunan as against 1 minute in the case of an admixture ofPerbunan with 25 percent of the plastic scrap rubber derivative. A

total time of 21 minutes was required to prepare 'Stock G and only 12minutes to prepare Stock J.

lus and tensile properties and the resistance to abrasion are materiallyenhanced. In order to show the superior resistance to attack by oils andsolvents, samples of the above described 5 stocks were immersed for '72hours at room temperature in various organic liquids and the percentincrease in weight after immersion noted. A minus figure indicates thatthere was a loss instead of a gain.

. Table IV It will of course be appreciated that it is unnecessary tocompound the synthetic rubber and the 1 in 1 11 ite rubber derivativeseparately. It is preterred to igfi gg fii 33 ,25 mix the plasticingredients first followed by the Stock Cum addiiton of the compoundingand vulcanizing in- 15 gredients. The aforementioned stocks were vul-Gamma Benzene Lubigfiafl x canized by heating in a press at thetemperature of 40 pounds of steam pressure per square inch A 40 152 o 06 and the modulus and tensile properties deter-' 2013 13810 013 40 23.7118.0 -0.s mined in known manner. 40 1 o 49' 3 6 l m a 1-3 ii 40 121019210 010 40 14.6 138.0 -o.s 40 13.1 121.0 1';4

Modulus of elasticity Cure in lbs./in. at elonga- Tensile U". Stock timein 12 elons, These results show that the resistance to oils and mins.solvents of oil resistant synthetic rubbers is further enhanced byadmixture with an 011 resistant product prepared by treating a rubber.with an 32 332 ggi 33g 30 aryl phosphine halide. is 1,000 1,860 330 Asfurther specific embodiments of the inven- 2 2% t; tion stocks werecompounded comprising: 1,010 1,825 330 1 v 35 Stock These data furtherillustate the improved modulus and tensile exhibited by the new composi-K L M N tions. v

The loss on abrasion was determined with the Pariahlzu' Parishbty Pam sPam s o 08! we: 1.0810 we: following results. 4o F 20 1/ 30 40 F Scraprubber derivative-. 70 60 50 Stearlc aci l 1 l l C a s- 2 2 2 2 ure incor e Stock time in Aprgsmn Di (benzothiazyl thiol) mins. BX dimethylurea l l l l 45 Diglhenylguanidine 0.5 0.5 0.5 0.5

M eral acid rearranged 45 114 2, 2, 4-trimethyl di- 45 108hydroquinoline...--... 2.0 2.0 2.0 2.0 45 Gastex 30 30 30 30Combinations of Perbunan and the plastic prepared from ground truckpeels are more resistant to abrasion than Perbunan alone,

While neoprene, Hycar and Perbunan are noted for their resistance toattack by oils and organic solvents, it has been found that theirdesirable properties in this respect are even further enhanced bycombining them with the aforemen tioned oil resistant products preparedfrom rubber and aryl phosphine halides. It is possible to preparecombinations includingvnatural rubber but while such combinationspossess more resistance to oils and solvents than the rubber alone, theimprovement is not significant. The presence of only a relatively smallproportion of rubber results in considerable swelling of the stock.Furthermore, even with relatively high proportions of rubber the modulusand tensile properties are considerably below. those of rubber alone. Onthe other hand admixtureof a. rubber-like polymer or co-polymer of abutadiene compoundwith an oil'resistant product derived from a rubberand aryl phosphine halide results in a number of significantimprovements.

As amply shown by the foregoing data the modu- Table V 1 Tensile atUltimate 60 Stock g g g g break in elongation,

lbs/in. percent The above dat show that compositions of improvedphysical properties are obtained by in- 75 creasing the proportion ofHycar up to a proportion of equal to that oi the plastic derived fromground truck peels. 'Stocks K, L, M and N i when considered with StocksD, E and F show 4 that the physical properties of eachplastic areimproved by combination up to approximately equal proportions of each.

The plasticity of the unvulcanized stocks was measured-by means of anextrusion plastometer. See J. H. Dillon, Rubber Chemistry andTechnology, 01. 9, pages 4 96-501 (1936) for a description of the methodand apparatus used. The quantity measured is the time in secondsrequired to'extrude a given volume of the stock at constant temperatureand under a constant pressure. In this particular instance twelve poundsof air pressure and a temperature of 180 F. was used.

Stock [Seconds These results show that the new compositions possesshighly desirable plastic properties. That is to say. the admixtures ofthis invention possess less resistance to flow than the individualplastic components and normal compounding of stocks according to thisinvention produces compositions which can be readily handled and procofnatural or synthetic origin. This invention is limited solely by theclaims attached hereto as part of the present specification.

What is claimed is:

1. A new plastic composition comprising an admixture of a rubber-likepolymer selected from the group consisting of polymers butadiene-1,3,polymers of 2-chlor butadiene-1,3, copolymers of butadiene-1,3 andstyrene and copolymers of butadiene-1,3 and acrylic nitrile and arubberlike vulcanizable oil resistant plastic obtained by 50 heating arubber with about an equal quantity of a crude aryl phosphine halide thehalogen being attached to. the phosphorus atom.

2. A new plastic composition comprising an admixture of a rubber-likepolymer selected from the group consisting of polymers of butadiene-1,3,

polymers of 2-chlor butadiene-1,3, copolymers of butadiene-1,3 andstyrene and copolymers of butadiene-1,3 and acrylic nitrile and arubberlilre vulcanizable oil resistant plastic obtained by heating arubber with 60-100 percent by weight on the rubber of a crude arylphosphine halide thehalogen being attached to the phosphorus atom in thepresence of an aromatic polynuclear hydrocarbon in 40-100 percent byweight on the rubber.

3. A new plastic composition comprising an admixture of a rubber-likepolymer'selected from the group consisting of polymers of butadiene-1,3,polymers or 2-chlor butadiene-1,3, copolymers of butadiene-1,3 andstyrene andcopolymers of butadiene-1,3 and acrylic nitrile and a.rubberlike vulcanizable oil resistant plastic obtained by heating arubber with 60-100 percent by weight on the rubber of a crude aryldichlor phosphine the two chlorine atoms being attached to thephosphorus atom in the presence of retene in 40-100 percent by weight onthe rubber. I 4. A new plastic composition comprising an ad- 5 mixtureofa rubber-like polymer selected from the group consisting of polymers ofbutadiene-1,3, polymers of 2-chl0r butadiene-1,3, copolymers ofbutadiene-1,3 and styrene and copolymers of butadiene-L3 and acrylicnitrile and a rubber.- like vulcanizable oil resistant plastic obtainedby heating India rubber with about an equal quantity of a crude aryldichlor phosphine the ,two chlorine atoms being attached to thephosphorus atom.

5. Anew plastic composition comprising an admixture of a rubber-likepolymer selected from the group consisting of polymers of butadiene-1,3,polymers of 2-chlor butadiene-1,3, copolymers of butadiene-1,3 andstyrene and copolymers of 0 butadiene-1,3 and acrylic nitrile and arubberlike vulcanizable oil resistant plastic obtained by heating scraprubber with 70-85 percent by weight on the rubber of a crude aryldichlor phosphine the two chlorine atoms being attached to thephosphorus atom in the presence of retene in 70-85 percent by-weight onthe rubber.

6. A new plastic composition comprising an admixture oi'a rubber-likeco-polymer of butadiene and acrylic nitrile and a-rubber-likevulcanizable oil resistant plastic obtained by heating a rubber withabout an 'equal quantity of a crude aryl dichlor, phosphine the twochlorine atoms being attached to the phosphorus atom.

7. A new plastic composition comprising an admixture of a rubber-likeco-polymer of butadiene v and acrylic nitrile and a rubber-likevulcanizable oil resistant plastic obtained by heating a rubber with60-100 percent byweight on the rubber of a crude aryl dichlor phosphinethe two chlorine 40 atoms being attached to the phosphorus atom in thepresence 01 retene in 40-100 percent by weight on the rubber.

8. A new plastic composition comprising an admixture of a rubber-likeco-polymer of butadiene 5 and acrylic nitrile and a rubber-likevulcanizable oil resistant plastic obtained'by treating India rubberwith about an equalquantity of a crude aryl dichlor phosphine the twochlorine atoms i being attached to the phosphorus atom.

9. A new plastic composition comprising an admixture of a rubber-likeco-polymer of butadiene and acrylic nitrile and a rubber-likevulcanizable oil resistant plastic obtained by heating scrap rubber withabout an equal quantity of a crude 5 aryl dichlor phosphine the twochlorine atoms being attached to the phosphorus atom.

10. An admixture of a rubber-like polymer of chlorbutadiene and arubber-like vulcanizable oil resistant plastic obtained by heating arubber with about an equal proportion by weight'of a crude aryl dichlorphosphine the two chlorine atoms being attached to the phosphorus atomin the presence of about an equal proportion by weight of retene.

11. A new plastic composition comprising an admixture of a rubber-likeco-polymer of butadiene and acrylic nitrile and a rubber-like,vulcanizable oil resistant plastic obtained by heating scrap rubber with-85 percent by weight on the 70 rubber of crude tolyl dichlor phosphineand technical retene in 70-85 percent by weight on the rubber.

12. A new plastic composition. comprising an admixture of a rubber-likepolymer of chlor buta- (5 diene and a rubber-like vulcanizable oilresistant plastic obtained by heating scrap rubber with .70-85 percentby weight on the rubber of crude tolyl dichlor phosphine and technicalretene in 70-85. percent by weight on the rubber.

13. A new plastic composition comprising an admixture of a, rubber-likepolymer selected from the group consisting of polymers of butadiene-1,3, polymers of 2-ch1or butadiene-LS, copoiymers oi butaGiene-LS andstyrene end copolymers oi

